The invention relates to a radar signal processing method for estimating the height of an object above a reflecting surface.
In addition to measuring the distance to the target, it is frequently desirable if radar devices can locate objects in the azimuth and the elevation or height in order to provide a better assessment of the situation in the surveillance range. A number of realized designs are known for this. Such known realized designs as a rule are connected to an expanded aperture of the antenna arrangement, which results in a focusing of the radiation output and makes it possible to purposefully detect a segment of the total surveillance range. Subsequently, the surveillance range is divided into several solid angle segments, which make it possible to provide more exact information on the position of an object. This aperture can either be real or artificial (SAR principle). However, at times it can be difficult to reconcile with the available space for installing the antenna arrangement, especially in the frontal area of motor vehicles.
The amplitude principle or the phase-monopulse operation principle, which permits small antenna dimensions, is furthermore known for the directional resolution in radar devices. In that case, the antenna must have at least two different individual patterns, which overlap.
As a result, known solutions for locating objects within the surveillance range generally are very involved with respect to the necessary device and have disadvantages concerning the costs for the device and/or its space requirement, particularly when used in motor vehicles.
Thus, it is the object of the present invention to specify a method for processing radar signals that permit locating objects, particularly an estimation of the height of the object above a reflecting surface, even if radar devices with little complexity and little space requirement are used.